Illuminated push button switch assembly including latching means



Dec. 28, 1965 w F. SCHUCHARD ILLUMINATED PUSH BUTTON SWITCH ASSEMBLY INCLUDING LATCHING MEANS Filed March 4, 1963 INVENTOR Dec. 28, 1965 w. F. SCHUCHARD 3,226,520

ILLUMINATED PUSH BUTTON SWITCH ASSEMBLY INCLUDING LATCHING MEANS Filed March 4, 1963 2 Sheets-Sheet 2 FIGS %MZLJ 2 INVENTOR.

ATTORN EYS United States Patent 3 226 520 ILL UMINATED PUSH llUT lflN SWITCH ASSEMBLY INCLUDING LATCHING MEANS Walter F. Schuchard, Hingham, Mass, assignor to S. H.

Couch Company, Inc., North Quincy, Mass, a corporation of Massachusetts Filed Mar. 4, 1963, Ser. No. 262,588 13 Claims. (Cl. 200-167) This invention relates to illuminated switches and more particularly comprises a new and improved interlocking illuminated push button switch assembly.

The illuminated interlocking push button switches presently available are rather large and complex and are consequently costly. It is an important objective of the present invention to simplify the construction and reduce the size and cost of such switches.

To accomplish these and other objects, the push button switch parts of the present invention are organized about the lamp and socket so that the depth of the assembly is substantially limited to the combined length of the lamp and socket employed. Thus, the limiting factor of the assembly depth is the lamp and socket combination rather than the combined length of the switch parts, lamp and socket.

These and other objects and features of the present invention will be better understood and appreciated from the following detailed description of one embodiment thereof, selected for purposes of illustration and shown in the accompanying drawing, in which:

FIG. 1 is a fragmentary perspective view of an interlocking illuminated push button switch constructed in accordance with this invention;

FIG. 2 is a fragmentary side view partly in section of the switch shown in FIG. 1;

FIG. 3 is a rear view of the switch shown in FIGS. 1 and 2; and,

FIG. 4 is an exploded perspective view of a portion of the switch shown in FIGS. 13.

The switch shown in the drawings is organized within a housing composed of a front panel 12 and a U-shaped channel 14. In FIG. 1, the panel 12 is shown to include inwardly directed flanges 16 spaced from the rear surface of the panel central wall to define slots 18 which receive the outwardly extending flanges 20 provided on the forward edges of the side walls 22 of the channel 14. Thus the housing may be assembled without the use of any visible fasteners.

Mounted in the housing are a plurality of substantially independent illuminated push button switch sub-assemblies. Each sub-assembly includes a cap or head 24 that extends through slot 25 in the front wall of the panel 12, and the caps may be depressed manually independently of one another to actuate their respective switches. In FIG. 1 three such caps are shown and the middle cap is in the depressed position while the others are in the released position.

An insulating block 26 riveted to the base 28 of the channel member 14 supports many of the switch components. It will be noted in FIGS. 2 and 3 that rivets 30 extend through the aligned openings 32 and 34 in the insulating block 26 and base 28 respectively, to secure the block to the channel. A light socket 36 of the bayonet type is mounted on the block 26, and its conducting stem 38 extends through the base of the socket and is electrically connected to terminal 40 carried on the rear face of the block. The terminal 40 and the other terminal 42 formed as an integral part of the socket and which projects through a slot 44 in the block, both extend out of the housing 14 through the rectangular opening 46 in the base 28 of the channel member 14. One such opening 46 is provided for each of the sub-assemblies as is evident in FIGS. 3 and 4.

In FIG. 4 lamp or bulb 58 is shown provided with a bayonet base which fits in the socket 36. When the base of the bulb 58 is inserted in the socket 36 the bulb base contact 60 engages the socket conducting stem 38 which is biased against the contact 60 by the spring 62.

The block 26 supports on opposite sides of the socket 36 two fixed contacts 48 and 50 which are disposed parallel to the side walls 22 of the channel member 14. Each of the fixed contacts 48 and 50 is provided with a flange 52 which sits on the upper face of the block 26 and is riveted in place. .by rivets which extend through holes 54 in the flange and'holes 56 in the block.

The other components of the sub-assembly are supported in the housing'on the channel member 14. It will be noted in FIG. 4 that the channel side walls 22 are provided with elongated slots 64 which extend from adjacent the channel base 28 to the region of the flanges 20. The slots 64 serve as tracks for the outwardly extending ribs 66 provided on each side of the switch button body 68. The body 68 has a pair of elongated side walls 70 disposed between the fixed contacts 48 and 50 and the sides 22 of the channel, and the walls 70 carry the ribs 66 on their outer surfaces. The outer surfaces of the side walls 70 lie against the inner surfaces of the sides 22 of the channel 14, and the ribs 66 extend into the slots 64 to restrict movement of the button body 68 to a path parallel with the axes of the socket 36 and bulb 58. The cap 24 snaps over the end 72 of the button body as is clearly evident in FIGS. 2 and 4. The caps 24 serve as lamp covers and are removable from the front end so that burnt out lamps can be replaced from the front.

The button body 68 carries a movable contact 74 which fits snugly within the side walls 70 and the shorter side walls 76. The contact 74 may be press fitted within the body, or the two parts may be fastened together by other convenient means. The contact 74 includes a pair of blades 78 which are generally parallel to and spaced inwardly from the side walls 70 of the body. One of the blades 78 is positioned to engage the fixed contact 48 when the button is in the released position and the other blade 78 engages contact 50 when the button is depressed.

A spring 80 surrounds the socket 36 and bears against the movable contact 74 to urge the button body 68 to its released or extended position wherein the ribs 66 are moved to an extreme position in the slots 64 with the ends 66' of the ribs bearing against the end wall 64' of the slots adjacent the flanges 20. When the body 68 is in its biased position, one of the contact blades 78 engages the bar 82 of fixed contact 48 to form a normally closed switch and the other blade 78 does not engage the bar 84 of fixed contact 50 and thus forms a normally open switch. The condition of each switch is reversed when the button body 68 and more particularly the cap 24 which extends through the panel 12 is depressed. It will be noted in FIG. 4 that fixed contact 48 has a cut-out 86 beyond its contact bar 82 so that when the blade 78 moves toward the base 28 of channel member 14, the tip 88 of blade 78 lies in the cut-out area and does not engage the fixed contact 48. Conversely, the fixed contact 50 has a cut-out 90 within which the tip 88 of the other blade 78 is disposed when the button body and cap are in the released position. Contact is made with the-contact bar 84 only when the button body is depressed against the bias of the spring 80.

A latching mechanism 92 serves to retain the bodies in their depressed position against the bias of spring 80. The latching mechanism includes an elongated locking plate 94 disposed outside the housing 14. As shown in FIGS. 1, 2, and 4, the plate 94 is disposed against the outer surface of and is substantially coextensive with one of the sides 22 of the channel member and lies close to the flange 20 on that side. The plate 94 has a longitudinally extending slot 96 at each end, and the slots overlie openings 98 in the adjacent channel side 22. Openings 100 are provided in the other channel side 22, aligned with the openings 98, and sleeves 102 internally threaded at each end serve as a spacer between the channel sides 22 and receive screws 104 and 106 as is evident in FIG. 4 to hold the assembly together. One screw 106 at each end of the housing extends through slot 96, a spacing washer 108, and opening 98 and threads into sleeve 102 to support the plate 94 for movement in a longitudinal direction on the channel side 22. The slots 96 at each end of the locking plate 94 define the limits of movement afforded the plate.

In FIG. 3 leaf spring 110 shown supported at one end by the screw 106, serves to bias theplate 94 in a raised position as viewed in that figure, and the plate may be moved against the bias of the spring as suggested by the broken lines so that it lies in a lowerlposition. The locking plate 94 has a number of transverseslots 112, each of which overlies one of the slots 64 in the side wall 22 of the channel member. The slots 112 receive pins 114 carried on the ribs 66 on the side walls 70 of the button bodies 68. The pins 114 cooperate with cams 116 provided on one side of each of the slots 112 intermediate the slot ends to retain the bodies in depressed positions against the bias of springs 80. In FIG. 2, the lowermost switch sub-assembly is shown in its released position and its pin 114 is on the right side of the cam 116. For the pin 114 to reach the other side 1118 of the cam 116 that serves as a keeper, a plate 94 must be moved downwardly so as to move the cam 116 out of the way of the travel of the pin. The inclined surface 120 of the cam 116 causes the pin 114 upon actuation of the body 68 towards its depressed position to move the plate '94 against the bias of the spring 110 until the pin passes the cam and is aligned with the keeper side 118. When the pin reaches that position, it effectively falls off the end of the cam edge 120, and the spring 110 returns the plate to the position shown in FIGS. 2 and 3 (in full lines). It will be noted in FIG. 2 that the subassembly next to the bottom is in the depressed position and its pin 114 lies in the keeper side 118, and the cam retains that pin and consequently its body 68 in the depressed position. FIG. 2 also reveals that when one of the sub-assemblies is in the depressed position, actuation of another of the sub-assemblies in the absence of the retaining force applied to the depressed sub-assembly, causes the depressed sub-assembly to move to its release position. Consider the effect upon the plate 94 when the lowermost sub-assembly in FIG. 2 is depressed. When that sub-assembly is depressed, its pin 114 will force the frame 94 downwardly which will cause the release of the pin 114 of the next upper sub-assembly from the keeper 118. That is, the crown 116' of the cam 116 of the next upper sub-assembly will lie below the pin 114 when the pin 114 of the lowermost assembly is about to drop into its keeper 118.

In the embodiment illustrated each lamp and switch subassembly includes a normally open and a normally closed contact, and the lamp socket serves as a distinct part of the switch circuit. The return spring 80 which surrounds the socket 36 and urges the switch body 68 to an extended position electrically connects the movable contact 74 and the socket 36, and a conductor connected to terminal 42 may serve as a lead common to both the switch and lamp circuits. If it is desired to divorce the lamp socket from the circuit of the switch or switches, an insulating sleeve may be used about the socket and within the spring to electrically insulate the two from one another.

In many applications only one or the other of the fixed contacts will be employed, and in certain applications the fixed contacts on one side of the housing may be connected together by a common bus bar extending the length of the block 26. In the fabrication of such an assembly all of the fixed contacts to be connected together may be integrally formed from a single piece of conducting material.

While in.the configuration of the invention illustrated a single locking plate 94 is provided it will be appreciated that a similar plate may be provided on the other side of the housing, and the two plates could work with different groups of switch assemblies. For example, in a twelve switch assembly the locking plate on one side of the housing could be operatively connected to six of the switches and the plate on the other side could be operatively connected to the remaining six switches. Obviously a wide variety of arrangements are possible. By eliminating the locking plates or the pins 114 carried by the button bodies 68 one or more of the switches may be converted to a non-locking momentary push button switch. It is also possible, using conventional techniques, to provide what is generally termed positive lock-out operation which prevents more than one button from being depressed at a time.

In use both terminals 40 and 42 and one or both of the fixed contacts may be connected to external conductors, and actuation of the push button switch may operate either or both of the lamp and switch circuits, depending upon how the circuits are connected. In a typical nurse-patient hospital communication system, the assem bly may be mounted in the nurses oflice, and one subassembly may be incorporated in the installation for each patients room to be monitored. A switch in each room will light its particular lamp in the office by a circuit connected to the socket terminals 40 and 42, and a speak-- er system between that room and the ofiice may be en ergized by depressing the push button switch of the particular sub-assembly so as to close the normally open switch in the speaker circuit. The assembly thus enables the patient by actuating a switch in his room to light his particular lamp in the office installation, and the nurse in turn by depressing the switch body can energize the communication system which enables the nurse and patient to communicate by voice with one another.

The foregoing description will suggest to those skilled in the art many modifications within the scope of this invention. Therefore, it is not intended that the breadth of the invention be limited to the single embodiment illustrated and described in detail. Rather, it is intended that the scope of this invention be determined by the appended claims and their equivalents.

What is claimed is:

1. An illuminated switch assembly comprising a panel,

a U-shaped channel member secured to and open in the direction of the panel and providing with the panel a housing for the assembly,

an insulating block secured to the base of the channel and carrying a lamp socketopen in the direction of the panel,

a pair of fixed contacts disposed on opposite sides of the socket within the channel,

a switch body disposed in the housing and including a pair of legs disposed immediately inwardly of the sides of the U-shaped channel member,

means provided on the legs and on the sides of the channel member cooperating to support the body for sliding movement toward and away from the fixed contacts,

a pair of contact arms carried by the body inwardly of the legs,

a spring surrounding the socket and bearing against the block and the switch body biasing the body to an outer position wherein the contact arms are disposed adjacent the outer ends of the fixed contact,

and latching means including a plate disposed outside the housing and operatively connected to the body for releasibly retaining the body in a. depressed posi.-

tion wherein the contact arms are disposed adjacent the inner ends of the fixed contacts.

2. A switch assembly as defined in claim 1 further characterized by the latching means including a support for the plate enabling the plate to move in a direction parallel to the panel,

a spring biasing the plate to a first position,

a slot formed in the plate extending generally parallel to the direction of travel of the body,

a pin carried by the body extending out of the housing and disposed in the slot,

a cam formed as part of the margin of the slot and in the path of travel of the pin when the body moves from the outer to the depressed position causing the plate to move from the first position to a second position against the bias of its spring when the body moves between those positions,

and a keeper disposed in the margin of the slot beyond the cam for retaining the pin and enabling the plate to return to its first position when the body is in the depressed position.

3. A switch assembly as defined in claim 1 further characterized by a cap removably mounted on the body and extending through an opening in the panel and providing a cover for a lamp mounted in the socket and a push button for the switch.

4. A switch assembly as defined in claim 1 further characterized by a pair of terminal posts disposed outside the housing and beneath the base of the channel member, one of said terminal posts being electrically connected to the socket and the other of said terminals being adapted to be connected to the base of a lamp mounted in the socket.

5. A switch assembly as defined in claim 1 further characterized by one of said fixed contacts being engaged by a contact arm when the body is in its outer position and the other of the fixed contacts being engaged by the other of the contact arms when the body is in its depressed position.

6. A switch assembly comprising a panel,

means cooperating with the panel to form a housing,

a plurality of illuminated push button switch subas-semblies carried by the housing and each comprising,

an insulating block in the housing,

a light socket mounted on the block,

a fixed contact disposed on the side of the socket and within the housing,

a body having a longitudinally extending axis and carrying a contact blade substantially in the plane of the fixed contact and movable between depressed and released positions, a spring surrounding the socket and urging the body to its released position wherein the contacts are in one condition,

latching means disposed outside the housing and engaging the body for holding the body in a depressed position upon restricted movement of the body along its axis against the bias of the spring, and in which position the contacts are in another condition,

and a translucent cap forming part of the body and disposed outside the panel and over the socket for manually actuating the body and for covering a lamp in the socket.

7. An illuminated switch assembly comprising a housing having a front panel and a pair of parallel side walls,

a plurality of illuminated push button switch subassemblies carried by the housing and each comprising,

an insulating block disposed in the housing and carrying a lamp socket,

a fixed contact mounted on the block adjacent the socket,

a switch body having a pair of legs disposed on the side walls of the housing and positioned to surround a lamp mounted in the socket,

means formed on the side walls and the legs for confining movement of the body along a path parallel to the axis of the socket between released and depressed positions,

a spring surrounding the socket and engaging the body urging the body to its released position,

and a movable contact carried by the body and extending generally parallel to the legs and engaging the fixed contact when the body is in one of its two positions, and means for holding selected ones of said bodies in said depressed positions upon movement of said bodies along said parallel paths.

8. An illuminated switch assembly as defined in claim 7 further characterized by said spring engaging the socket and movable contact electrically connecting the two together.

9. An illuminated switch assembly as defined in claim 7 further characterized by a locking plate disposed outside the housing and operatively connected to the body for releasably retaining the body in a depressed position against the action of the spring.

10. An illuminated switch assembly as defined in claim 7 further characterized by said holding means comprising a locking plate disposed outside the housing and operatively connected to a plurality of the bodies for retaining each of these bodies in a depressed position against the action of the spring,

and means forming part of the locking plate for releasing depressed bodies when another body is depressed.

11. An illuminated switch assembly as defined in claim 7 further characterized by a cap removably mounted on the body and extending through the panel and providing a push button for the switch and a cover for a lamp mounted in the socket, said cap exposing the socket when the cap is removed from the body enabling a lamp to be mounted in the socket through the panel.

12. An illuminated switch assembly as defined in claim 7 further characterized by a pair of tracks provided in the panel,

and flanges secured to the side walls and slidably mounted in the track to removably secure the housing together.

13. An illuminated switch assembly as defined in claim 8 further characterized by a terminal post connected to the socket and extending out of the housing and adapted to be connected to a lead common to a lamp and switch circuit.

References Cited by the Examiner UNITED STATES PATENTS 1,778,186 10/1930 Douglas 2.00169 2,863,028 12/1958 Fraser et a1 200-167 KATHLEEN H. CLAFFY, Primary Examiner.

BERNARD A. GILHEANY, Examiner. 

6. A SWITCH ASSEMBLY COMPRISING A PANEL, MEANS COOPERATING WITH THE PANEL TO FORM A HOUSING, A PLURALITY OF ILLUMINATED PUSH BUTTON SWITCH SUBASSEMBLIES CARRIED BY THE HOUSING AND EACH COMPRISING, AN INSULATING BLOCK IN THE HOUSING, A LIGHT SOCKET MOUNTED ON THE BLOCK, A FIXED CONTACT DISPOSED ON THE SIDE OF THE SOCKET AND WITHIN THE HOUSING, A BODY HAVING A LONGITUDINALLY EXTENDING AXIS AND CARRYING A CONTACT BLADE SUBSTNATIALLY IN THE PLANE OF THE FIXED CONTACT AND MOVABLE BETWEEN DEPRESSED AND RELEASED POSITIONS, A SPRING SURROUNDING THE SOCKET AND URGING THE BODY TO ITS RELEASED POSITION WHEREIN THE CONTACTS ARE IN ONE CONDITION, LATCHING MEANS DISPOSED OUTSIDE THE HOUSING AND ENGAGING THE BODY FOR HOLDING THE BODY IN A DEPRESSED POSITION UPON RESTRICTED MOVEMENT OF THE BODY ALONG 